228 
CHARLES O. APPLEMAN 
Table I 
Respiration of McCormick Potatoes After an Exposure of the Tubers to Ethyl Bromide 
Gas for Thirty Minutes 
Date of Measure- 
ment 
Time Elapsed 
Alter Treatment 
with Ethyl 
Bromide Gas 
Milligrams of CO2 per Kilo per Hour 
Ratio 
Untreated 
Ethyl Bromide 
Gas — 30 Min. 
February 12 .... 
February 24 ... . 
I hour 
12 days 
19.17 
16.60 
37-94 
18.54 
I : 1.98 
I : 1.27 
Table II 
Oxidase Activity in Juice from McCormick Potatoes After an Exposure of the Tubers 
to Ethyl Bromide Gas for Thirty Minutes 
Experiment 
Time Elapsed 
After Treatment 
with Ethyl 
Bromide Gas, Hours 
Quantity of Juice 
Used, Cc. 
Manometer Readings Expressed in 
Centimeters of Mercury- 
Untreated 
Ethyl Bromide 
Gas — 30 Min. 
I 
3 
4 
5 
6 
Average 
I 
I 
2 
24 
24 
48 
I 
I 
-5 
•5 
.2 
•33 
- 4-4 
- 4-5 
- 3-0 
- 3-2 
- I.O 
-2.5 
- 4-5 
- 4-5 
- 3-2 
- 3-4 
- I.O 
- 2.5 
-3.1 
3-18 
Catalase Activity in Juice from McCormick Potatoes After an Exposure of the Tubers 
to Ethyl Bromide Gas 
Time Elapsed After Treat- 
Manometer Readings Expressed in Centimeters of Mercury 
Experiment 
ment with Ethyl Bromide 
Gas— Hours 
Untreated 
Ethyl Bromide Gas — 30 Min. 
I 
20 
+ 2.6 
+ 3-5 
2 
21 
+ 2.2 
+ 3-6 
3 
40 
+ 2.0 
+ 3-5 
4 
40 
+ 2.4 
+ 3-5 
Average .... 
+ 2.3 
+ 3-53 
Cold Storage: If tubers are stored for a few weeks at low tempera- 
tures and then brought to room temperature, they respire much 
more rapidly than tubers of the same lot which were not subjected 
to the cold storage. The effect on the catalase and oxidase is almost 
identical with that under the ethyl bromide treatment, if the cold 
